Sponsor Decision- Financial Considerations

The purpose of this study is to determine if the combination of naltrexone SR and fluoxetine is more effective in treating the symptoms of obsessive-compulsive disorder (OCD)than either fluoxetine alone or naltrexone SR alone.

Inclusion Criteria:

• Male or female subjects, 18 to 60 years of age (inclusive)
• Outpatients with a current diagnosis of OCD that have received previous therapy
• Negative serum pregnancy test as screening in women of child-bearing potential
• If a woman of child-bearing potential, must agreed to use an acceptable and effective form of contraception
• No clinically significant abnormality on electrocardiogram (ECG)
• No clinically significant laboratory abnormality at screening
• Negative urine drug screen
• Must be considered reliable and possess a level of understanding that enables the subject to provide written informed consent and to comply with protocol procedures and schedule

Exclusion Criteria:

• Diagnosis of substance dependence
• Diagnosis of substance abuse (except for nicotine and caffeine)
• Serious or unstable medical illnesses
• Lifetime history of bipolar disorder, schizophrenia or other psychosis, bulimia, anorexia nervosa, Pervasive Developmental Disorder (PDD), Asperger's Syndrome or the presence of antisocial or borderline personality disorder
• Diagnosis of tic disorder or Tourette's Syndrome
• Subjects diagnosed with impulse control disorder
• Known sensitivity or allergic reaction to either naltrexone or fluoxetine
• Any condition which in the opinion of the investigator or Sponsor makes the subject unsuitable for inclusion in the study
• Immediate family of investigators, study personnel or Sponsor representatives